Mammalian target of rapamycin, otherwise known as mTOR, is a protein kinase that regulates many cell activities including growth, proliferation and protein transcription. mTOR has been associated with human processes and diseases including aging, transplant rejection and cancer. Many mTOR inhibitors have been identified and/or developed including: rapamycin and analogs thereof, temsirolimus, everolimus, ridaforolimus, sirolimus and deforolimus. Some mTOR inhibitors have been approved for use by health authorities for treatment of various cancers and transplant rejection.
A side effect common in patients receiving mTOR inhibitors is known as mTOR inhibitor-associated stomatitis (mIAS). Incidence of mIAS is estimated at 40-90% of all patients being treated with mTOR inhibitors. Although usually not life-threatening, mIAS occurrence in patients may be painful and may interfere with a patient's routine daily activities such as eating and drinking. Occurrence of mIAS may require reduction of mTOR inhibitor dose or cessation of treatment, thereby limiting the efficacy of the mTOR inhibitor treatment.